Week 4

AIM :

For the given component, check for any geometrical errors and capture all the elements and mesh with the prescribed element Quality criteria. The number of traingular elements should be as less as possible with a smooth mesh flow.

Step 1: The 1st step is to set Part ID and assign material for the given component and check for any Geometrical errors in the component by using Topo command in Faces module. The errors should be eliminated before proceeding with further activities. The errors can be eliminated by using Checks Manager window, click execute on the visible entities. Those errors popped up can be fixed by using selecting all the errors and right click on mouse and select on fix. However it is recommended to go and manually check the errors and resolve them.

Step 2: Next step is to carefully select the faces seperately and take mid plane for those faces one by one.

• Image 1 and 2 shows that the mid plane for an feature like a Ratchet teeth can be taken by clicking on the Middle on the Curves module on the both the opposite faces of the feature. Image 3 shows that the using the 2 curves created, a new face can be created by clicking on New command in Faces module. Generally Coons or Fitted face option is chosen for these type of two parallel but different geometry.
• The same above steps can be followed for for all the similar features. But it is time consuming time. So to save time a special command can be used by creating a center point for axis of rotation and selecting the first element for rotation. That can be done by first clicking on On Cog command in Pionts and then clicking any two circles with same center (concentric) with different heights, so that 2 different points are generated. After this go for copy under Transform command and select rotate. Under X, select the first point and under dX, select the second point. An axis is being created for rotation. The angle should be the angle of rotation(in degrees) of selected element across the center axis divided by total number of features present across the circle. The total number of features to be created is one less than the total, because it will be already selected for Copying. Image 4 and 5 depicts the same steps. Which is 360/12=30 degrees, where 360 is the total angle of rotation, 12 is the total No of features present and 11 is the number of features to be copied
• The previous step can be followed to other feature that are present in circular pattern but with vrying parameters.
• After creating the midplane, the most important command, i.e., Extend command under Faces module is being used to extend the end of the mid plane to the mid plane of the opposite face, where both connect and replicates the actual CAD model.
• Image 6,7,8,9 shows that the middle to curves can be used to create a middle curve so that it is projected onto the face where the mid surface should be created by clicking on Project in cons module and selecting the curve to be projected and the face on to which it has to be projected. By creating a new face between the two curves in middle, a mid surface is generated which replicates the actual CAD model.
• Image 10,11,12,13 shows a teeth feature, where same steps like curves to middle is created and the opposite con is turned into a curve using cons2curves and the middle is being created using New command. After one element is created, the other 35 features are created as explained earlier.
• To create Mid srface for a thread feature, initially Mid to curves as shown in Image 14 is being taken. After this, a curve is created perpendicular to the curve which was created csing Create command in Curves Module at two end faces of the helical feature. After this, a new face is created alon the new curves created using New command in Faces module. Image 14 to 17 shows the same.

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STEP 3: Meshing. The following steps are followed to create the mesh.

• Mark/un" Command to mark the hot points module so that it won't change its position during meshing.
• "Project" command in Hot points module to copy the hot points to any neighbouring cons and "parametric" to enter the values to specific point from the start point.
• "Num+/-" command in Perimeters module to increase(with left mouse click) and decrease(with right mouse click).
• "Slide" in Perimeters module to rotate holes/hollow regions so as to allign it for smooth mesh flow.
• "Cut" command in Macros module (left mouse click) to insert new con and (right mouse click) to erase.
• "Join" command in Macros module (left mouse click) to remove the inserted con. Note that "Keep" option to be checked in options list at the bottom corner of the ANSA GUI.
• "Best" command in Mesh Generation module to mesh the user chosen surface.
• "Improve" and "Smooth" commands in Shell Mesh module to improvise the mesh generated.
• "Split" command in Elements module. Left mouse click on the con will insert the cons in a rhombus pattern with edges box checked in and right mouse click on the con will Swap the con to a neighbouring element.
• "Swap" function is used to interchange neighbouring elements with each other.

The below image shows mesh generated for the given component.

The mesh itself is given a new PID.

Conclusion:

As per the meshing Quality criteria prescribed, the component is being created with the mid surface and the mid surface generated is being meshed with smooth mesh flow and with minimum triangular elements.

The link for model:

https://drive.google.com/file/d/1qqi54PkxPbzaJV3vmuQXT6E28qxoyhib/view?usp=sharing